Tension-spool for roll-holders



(Modem T. M. CLARK.- TENSION SPOOL FOR ROLL HOLDERS.

No. 530,327. "Patented Dec. 4, 1894.

Fig. 1 I

Fig.2.

G (l d s Fig.3. W T

cw A /A\ /A\ /A\ A -l l l vvvvv/ 11 Wimcsscs. Inv'cnfor 4.2M. j Jpu. fiazdkxze NITED STATES PATENT OF CE.

THEODORE MINOT CLARK, OF NEWTON, MASSACHUSETTS.

TENSION-SPOOL FOR ROLL-HOLDERS.

SPECIFICATION forming part of Letters Patent No. 530,327, dated December 4, 1894. Application filed June 26, 1894:. S rial N 515,753. (Model-l To all whom, it may concern:

Be it known that I, THEODORE MINOT CLARK, of Newton, in the county of Middlesex and State of Massachusetts, have in- 5 vented certain new and useful Improvements in Tension-Spools for Roll-Holders, of which the following is a specification.

The object of this invention is to provide an improved construction of spool, bobbin or p reel with provision for placing a tension on the commodity carried by it and maintaining a stretch of the same always taut by a tendency to rewind it.

The invention is capable of embodiment in r many difierent forms for many different uses.

It is here shown in a form adapted for holding the sensitive film commonly used in cameras, and the invention may be said to be particularly useful in this connection as it provides for keeping the stretch of film extendlug across the camera perfectly smooth, and at the same time no tension device bears against the film and it is not in any wayimpaired. z 5 The accompanying drawings forming part of this specification illustrate an embodiment of the invention.

Figure 1 shows a longitudinal section of a cylinder which forms part of the device, the heads of the cylinder being represented as separated from the main or body portion. Fig. 1 shows a face view of one of the cylinder-heads. spindle and spring forming part of the de- 35 vice.

Fig. 3 shows the complete device with the cylinderin section and the spindle and spring in elevation. Fig. 4 shows a section on line 4-.4. of Fig. 3.

The letter, T, designates a cylinder of suitable material as thin sheet-metal, paste-board or the the like, whose ends are designed to be closed by heads, 0, in the form of circular disks stamped out with flanges, c, to fit in the cylinder. These heads may be fastened with solder or in any other suitable manner, the flanges afiording means for fastening. The heads, 0, have central openings for a spindle, S, which is round throughout 50 the greater portion of its length, the cylinder Fig. 2 shows a side elevation of a Fig. 2 showsan end view of the same.

being designed to rotate upon it. The ends of this spindle are flattened to'fit correspondingly formed sockets in a suitable support which prevents the spindle from turning. A spring, W, of spiral form surrounds the central portion of the spindle, and one end of said spring is secured thereto by being passed through it and bent over.

The parts are assembled in the following manner: One of the heads, 0, is fastened in the cylinder, and the spindle, S, with spring attached is inserted in the cylinder, and the end of the spindle introduced through the central hole in said head. The normal compass of the spring is such as to require its compression to a certain extent in order to insert it in the cylinder, and hence it will press against the interior surface of the cylinder. After the spindle and spring have been inserted in the manner described, the other head, 0, is fastened in the end of the cylinder.

Unwinding of the film or whatever else may be wound upon the spool, is resisted. by the spring so that when the device is in use this spring constantly tends to turn the spool back and Wind up the film by reason of its torsional action. Hence, a stretch of the film drawn off from the spool will always be kept taut.

The frictional engagement of the spring with the walls of the cylinder caused by its expansive tendency is sufficient to produce a torsional strain on the spring when the cylinder is turned, and a tendency of the spring to rewind the film.

In filling the spool it will be supported so that the spindle and cylinder may turn together, and the spring will not offer any re sistance. I

The heads, 0, of the cylinder may be pro- 0 vided with holes, h, to receive the forked ends of suitable trunnions or other supports which may be used to hold the spool while it is be ing filled.

When the cylinder is made of sheet-metal 5 it will be covered with paper to which the film can be conveniently attached.

It will be observed that the heads, 0, extend beyond the cylinder to form confining flanges for the film. zoo

spiral retracting spring fastened to said spin die and surrounding the same and extending longitudinally within the cylinder in frictional engagement with the walls thereof.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 13th day of June, A. D. 1894.

THEODORE MINOT CLARK.

Witnesses:

HORACE BROWN, A. D. HARRISON. 

